//抽象一个公共函数
const timeout10 = (str, timeout = 10) => {
    return new Promise((resolve, reject) => {
        setTimeout(() => {
            resolve(str);
        }, timeout);
    });
};

//主函数
(async function main() {
    //可以进一步抽象，看需求
    let a = await timeout10("hello");
    let b = await timeout10("lagou");
    let c = await timeout10("I ❤ U");
    console.log(a + b + c);
})();
